Offshore well drilling apparatus



June 22, 1965 Filed Sept. 11, 1963 G. D. JOHNSON ETAL OFFSHORE WELLDRILLING APPARATUS 2 Sheets-Sheet 1 FIG- 2 INVENTORS.

GLENN D. JOHNSON BRUCE J. WATKINS THEIR AGENT June 22, 1965 a. D.JOHNSON ETAL 3,190,353

OFFSHORE WELL DRILLING APPARATUS 2 Sheets-Sheet 2 Filed Sept. 11, 1963FIG. 4

FIG.

INVENTORSI GLENN o. JOHNSON BRUCE J. WATKINS BY: 4.1M.

THEIR AGENT United States Patent "ice 3,190,358 OFFSHORE WELL DRELLINGAPPARATUS Glenn D. Johnson, Downey, and Bruce J. Watkins, Palos VerdesEstates, CalitZ, assignors to Shell Gil Company, New York, N .Y., acorporation of Delaware Filed Sept. 11, 1963, Eer. No. Sit-3,267 6Claims. (Ci. 166-665) This invention relates to the drilling of oil andgas wells, and pertains more particularly to a method and apparatus fordrilling offshore wells wherein the wellhead assembly is positioned onthe ocean floor or a considerable distance under the surface of a bodyof water.

During recent years the continued search for oil has resulted indeveloping methods and apparatus for drilling underwater wells atlocations where the Water may range from 100 to 1500 feet or more indepth. In these locations it is customary to position the wellhead at aconsiderable distance below the surface of the water, preferably on theocean floor, so that it is not a hazard to the navigation of ships inthe area. During well drilling operations it is often necessary tosuspend two or more concentric strings of pipe casing or tubing from adrilling structure or vessel on the ocean surface with the pipe andtubing extending down into the well drilled in the ocean floor. Aproblem arises in providing the necessary pipe engaging and pipesupporting apparatus on the crowded operating floor of a drill rig inorder to safely and adequately temporarily suspend multiple concentricstrings .of pipe.

A primary object of the present invention is to provide offshore welldrilling apparatus whereby multiple concentric strings of pipe extendingfrom an underwater Well to a point above the surface of the ocean may beindividually engaged and supported in a temporary manner.

A further object of the present invention is to provide a drillingvessel having multiple operating decks provided with apparatus forsuspending each of a pair of concentric pipe strings from a separateoperating deck of the vessel.

Another object of the present invention is to provide a drilling vesselwith suitable pipe supporting apparatus whereby a string of easing maybe suspended from one deck and extend into an underwater well while adrill string extends from a second deck through the casing and in thewell.

These and other objects of this invention will be understood from thefoil-owing description taken with reference to the drawing, wherein:

FIGURE 1 is a diagrammatic view illustrating a floating drilling vesselposition over a drilling location while supporting concentric strings ofpipe therefrom;

FIGURE 2 is a longitudinal fragmental view diagrammatically illustratinganother arrangement of suspending concentric pipe strings from thevessel illustrated in FIGURE 1;

FIGURE 3 is a fragmental view taken in longitudinal cross sectionillustrating two forms of pipe supporting equipment adapted to be usedon the drilling vessel of FIGURE 1;

FIGURE 4 is a view taken in longitudinal cross section illustrating thelower pipe support on the auxiliarly deck of FIGURE 3 when raised to itsvertical non-operative position; and

3,19%,358 Patented June 22, 1955 FIGURE 5 is a plan view of the pipesupport structures on the lower or auxiliary deck of the vessel as shownin FiGURE 3.

Referring to FIGURE 1 of the drawing, an offshore structure for carryingout well drilling, completion and workover operations is shown. Adrilling barge, vessel, or platform 1-1 of any suitable floating orfloatable type is illustrated as floating on the surface of a body ofwater 12 and fixedly positioned over a preselected drilling location bybeing anchored to the ocean floor by anchor lines 14 and 15 running toanchors (not shown). Equipment of this type may be used when carrying onwell drilling operations in water varying from about feet to 1500 feetor more. The drilling vessel is equipped with a suitable derrick 16containing a fall line system, including a travelling block 17, a hoist18, a drilling swivel and/ or an elevator 19. The barge 11 is alsoprovided with other auxiliary equipment neede during the drilling of thewell, such for example as a rotary table 2% positioned on the operatingdeck 21, a hinged slip-and-spider assembly 22 positioned on the lowerdeck 23, etc. The elevator 19 is normally provided for suspendingtherefrom, during certain of the drilling operations, a drill string 24or the kelly section at the top of the drill string while theslip-and-spider assembly 22 is adapted to secure fixedly a string ofpipe, for example, a string of surface casing 25 against a verticalmovement relative to the vessel 11.

During the actual drilling operations during which the kelly at theupper end of the drill string 24 is positioned in and rotated by themaster bushing 26 in the rotary table Zii, it is to be understood thatthe kelly and rotary table could be replaced by a power swivel (notshown) in a manner well known to the art. The derrick 16 is positionedover a drilling slot, or well 26, which extends vertically through thevessel in a conventional manner. When using the equipment of the presentinvention, the slot 25 in the barge 11 may be either centrally locatedor extending from one edge. However, drilling operations may be carriedout over the side of the barge without using a slot. It is also to beunderstood that in some areas the apparatus and method of the presentinvention may be utilized when operating from either a permanently fixedplatform, or a temporarily fixed and normally iloatable platform.However, for purposes of illustration, the present invention will bedescribed with regard to its use when drilling and completing a wellfrom a floating barge which is preferably anchored but not necessarilyso. In many drilling operations, the floating vessel may be maintainedin a rela tively fixed position on the surface of the ocean by means oftwo or more outboard motors or other marine propulsion units arranged toact in our position.

The operating deck 21 of the offshore structures provided with avertical opening 27 While the lower or auxiliary deck 23 is providedwith a second vertical opening 28. Both the first and second openings 27and 28, respectively, are in vertical axially alignment. The operatingdeck 21 may also be provided with support beams 30 and 31 on oppositesides of the first opening 27 for supporting the rotary table 2%)thereon. If desired, the high beams 30 and 31 may be removably securedto the deck 21 so as to give a larger opening through the deck whenlowering large equipment down to the underwater wellhead. Preferably,the spacing between the operating deck 21 and the auxiliary deck 23 issubstantially equal to a normal length of pipe, say 20 feet, used tomake up a drill string 24. Thus, the elevator 19 may be able to engageand suspend the upper end of the pipe section while the lower tool jointwas being made up or broken on the auxiliary deck level.

The pipe-engaging and supporting apparatus used on the auxiliary deck 23in supporting the pipe string 25 is preferably'a slip-and-spiderassembly 22 of any conventional design; The slips32iare wedge shapedelements having handles 34'to facilitate Wrapping them aroundthe pipe 25and inserting them into the hinged casing spider 22. The spiderisprovided with. suitable handles 35 whereby it may be pulled apartalong joint 36; When not in usethe casing spider 22 may be openedta ndpulled to one side. of theopening 28 through the auxiliary deck 23 bysliding it along the deck or in any other suitable manner, as willbedescribed hereinbelow. One suitable type of a casing spider ismanufactured by the Baash- Ross Tool Company of .Houston', Texas, and isdescribed in the Composite Catalog'of Oil Field Equipment and 4 suitablemanner as by ticing it back with a rope 53 connected to a ring 54. V

'In moving the casing spider 22 and its platform 44 out of the way whena pipe string was extending down through the opening in the auxiliarydeck 23 of the vessel, the lock pin 42 (FIGURE 5) would be pulled up andthe two halves of the casing spider 22 opened after the slips had beenremoved therefrom. The two halves of the casing spider 22 would bepulled back until they were stopped by locks 55 and 56 welded to the topof the platform 44. The platform 44 wouldthen be raised to itsverticalpositionas shown in FIGURE 4 with the casing spider restingagainst the blocks 55 and 56. I I

While the normal pipe engaging andsupportingmeans for use on theoperating deck 21 would comprise slips 38 being used in conjunction withthe rotary table 20 as described with regard to FIGURE 2, if desired,the rotary table 20 maybe removed and substituted for. a second casingspider diagrammatically represented by element 58 assurroundinglthe.pipe string .24 extending .up through theopening 2'7. in'the operatingdeck, 21 (FIGURE 3 A split type casing bushing. 59 having handles 60 maybe inser'ted inthe casing .spiderxin. a manner well known to the'artwith use of smaller diameter p'ipes,it beingunderstood'thatzasuitable set ,of slips similar to those. described awith regard to 'slip's 32 would be inserted in the pipe string with thatdescribed with regard to FIGURE 1 with slips 32 engaging the largediameter pipe string whilebeing 1 positioned within the casing spider22., On the operating deck 21, the masterbushing 26 (FIGURE 1),ifrequired,

is removed from the rotary'table 20 and is replaced by casing supportingtable bushing (not shown). A set of slips 38 having handles 39 are inpipe-supporting engagement with the table bushings for supporting thesmaller pipe 24, the latter being positioned in the vertical openingthrough the rotary table-20.." This leaves the elevator v19 free toengage the upper end of the pipe-string 24 as desired, or to support atool or a third string of pipe if desired.

One form of a' slip-and-spider assembly is shown in greater detail inFIGURES 3 and 5. As shown in FIG- URE-5 the casing spid er 22 is made oftwo parts spread along lines 40 and provided with a hinge pin'41 at oneend ailock' pin 42 at the other, end. Thus, to remove the casing spider22 from around a pipe-sectionpassing therethr'ough, the .lock pin 42would be pulled out and able manner, asv by mounting it on wheels tomove it laterally on the auxiliary deck 23 or providing itwith a hinge45 adapted to be secured to a cooperating hinge 46 Welded to the deck23, the hinges being connected by means of a hinge pin 47 extendinghorizontally. The otherend of 'theplatform-M maybe secured to the deck23 by any suitable means, as by a removable bolt 48.

Asshown in FIGURES the platform 44 is preferably bifurcated havinglaterally extending arms 50 and 3 51 arranged in parallel spacedrelationship and of the length to stand the, opening 28 through theauxiliary deck 23.

As maybe seen in'FIGURE 3,v the pivot pin 41 extends entirely throughthecasing spider 22 and is fixedly secured at its lowerend tothe platform44fso that thecasing spider- 22 remains on the top of the platform 44when thelatter is iraisedto its vertical position as shown in FIGURE 4.The platform 44 or casing spider 22 may rest against. a suitable support52 on the drilling vessel andthe equipment may be maintained'in place inany 24 and the casing bushing 59 when it was desired to supportthe'pipestring 24..therein. a

This application is a continuation-impart.application of copendingapplication Serial No. 79,842 filed December 30,1960... I

We'claim'as-our invention: g V 1. An offshore structure for carrying outwell drilling and completion and ,well work-over operations, saidstructure adapted to be. positioned .at.a .selected. offshore locationin a manner sufiiciently stationary to carry out operations wherein pipemeans-may ,:be supported ;at two vertically-displaced levels, saidstructure comprising an operating deck having a vertical firstoperiingthere.-

throughof a isize-suflicient to pass well tools and 7 equipmenttherethrough. an auxiliary-lower deck 'poistioned. below said operat-"ingdeck and having a verticalsecond .openingtherethrough at leastsimilar in .size to said first opening in said operating deck and invertical alignment therewith,"

7 .first pipe-engaging means supported by. said. operating deck andarranged concentrically relative to openingin said.deck,.. l secondpipe-engaging means carried by said auxiliary deck andadaptedfto bepositioned concentrically relativeto said second openingin saidauxiliary deck, said. second. pipe-engaging means being movablypositioned on said auxiliary deck for-movement into and out ofalignment. with said'openingin said deck, and movable platform meansinterposed between said second pipe-engaging means and .said auxiliarydeck for movement into a'ndoutof alignment with said opening in saiddeck for supporting said second pipesaid first engaging means. 2.Theapparatus. of claim:1 including vertical pivot pin means securing:said second pipe-engaging means to said movable platform means.

means, is bifurcated/with arms extending on either side of the axisofflsaid second opening through said auxiliary decks...

3. Th'e apparatus of claim 1 including horixontal pivot pinmeans;inengagementwithone side of said platform means and said auxiliarydeck to one side of said second opening tlierethro'ughv whereby saidplatform means is movable from a horizontal position to a substantiallyvertical position; I

4. The apparatus of claim 3 wherein said platform 5. The apparatus ofclaim l -including vertical pivot pin vmeans in engagement between saidsecond pipe-engaging means and said platform means at a pointintermediate 1,894,093 1/33 Hill 175-171 said horizontal pivot pin meansthereof and the axis of 2,068,217 1/ 37 Abegg 24-263.5 said secondopening through said auxiliary deck. 2,628,818 2/53 Graham 175-9 6. Theapparatus of claim 1 wherein said offshore struc- 193 34 4 1 Bauer et 1175 5 ture is a floating structure at least when being moved to2,988,144 6/61 Conrad X an Offshore locatlon- 3,015,360 1/62 Stratton16666.5 x References Cited by the Examiner 310431255 7/62 Bauer et a1175 7 X UNITED STATES PATENTS 3,077,227 2/63 Haeber 166-665 X 1,448,1723/23 Wellensiek 175171 10 CHARLES E, OCONNELL, Primary Examiner,

1. AN OFFSHORE STRUCTURE FOR CARRYING OUT WELL DRILLING AND COMPLETIONAND WELL WORK-OVER OPERATIONS, SAID STRUCTURE ADAPTED TO BE POSITIONEDAT A SELECTED OFFSHORE LOCATION IN A MANNER SUFFICIENTLY STATIONARY TOCARRY OUT OPERATIONS WHEREIN PIPE MEANS MAY BE SUPPORTED AT TWOVERTICALLY-DISPLACED LEVELS, SAID STRUCTURE COMPRISING AN OPERATING DECKHAVING A VERTICAL FIRST OPENING THERETHROUGH OF A SIZE SUFFICIENT TOPASS WELL TOOLS AND EQUIPMENT THERETHROUGH. AN AUXILIARY LOWER DECKPOSITIONED BELOW SAID OPERATING DECK AND HAVING A VERTICAL SECONDOPENING THERETHROUGH AT LEAST SIMILAR IN SIZE TO SAID FIRST OPENING INSAID OPERATING DECK AND IN VERTICAL ALIGNMENT THEREWITH, FIRSTPIPE-ENGAGING MEANS SUPPORTED BY SAID OPERATING